Simultaneous Spatial and Frequency-Domain Filtering at the Antenna Inputs Achieving up to +10dBm Out-of-Band/Beam P1dB

📋 论文概要

该论文提出了一种在天线输入端同时实现空间和频域滤波的技术，旨在提高多天线收发器的线性度。通过全无源开关电容网络，实现了高达+10dBm的带外/波束外输入参考1dB压缩点（P1dB），显著改善了传统方案的线性度与噪声折中。

💡 主要创新点

• 首次将空间滤波和频域滤波结合在天线输入端，同时实现波束选择和频率选择，提高带外/波束外线性度。
• 采用全无源开关电容网络，避免了有源器件的非线性，使P1dB达到+10dBm，同时保持较低的噪声系数。

🏷 关键词

📄 原文摘要

Multi-antenna transceivers with beam-forming are recently gaining interest for low GHz frequencies (<6GHz) [1-4]. In the antenna beam, (phase-shifted) signals from multiple antennas add constructively, improving SNR, while out-ofbeam signals add destructively (i.e. spatial filtering). Usually the summation point is behind some gain blocks, which then need to be capable of handling strong signals. To improve the input-referred compression point P1dB, a fully passive switched-capacitor approach was presented in [4], providing P1dB=+2dBm, but at a high noise penalty: NF=18dB. Here we propose to sum immediately at the baseband capacitors of passive mixer-first switched-RC downconverters. We show that this can render a direction-dependent RF impedance (spatial filtering) together with RF bandpass frequency filtering at lower noise and higher P1dB. The proposed architecture is shown in Fig. 5.2.1 for a 4-element phased-array.

👥 作者与机构

Amir Ghaffari, Eric E.A.M. Klumperink, Frank van Vliet, Bram Nauta

University of Twente, Enschede, The Netherlands